1. Field of the Invention
The present invention relates to hand tools and, in particular, to tools incorporating a bit holder for receiving interchangeable bits, such as screwdriver bits or the like. The invention has particular application to tools in which bits are magnetically retained in a bit holder.
2. Description of the Prior Art
Typical current magnetic bit holders include a cylindrical body having a socket formed axially in one end thereof for mateably receiving an associated bit. The inner end surface of the socket has further formed therein an axial hole of reduced cross section receiving an associated magnet to retain the bit in place in the socket. A suitable permanent magnet is press-fitted or crimped into the magnet hole for magnetically retaining the associated bit in place. The magnet is commonly formed of a material such as Alnico and has considerable mass, typically being approximately one inch long and approximately one-quarter inch in diameter.
Other permanent magnet materials, such as neodymium, have been provided which can afford greater magnetic holding power with significantly reduced magnet mass. However, neodymium magnets are extremely brittle and cannot be press fit or crimped, nor can they be impacted in use by a bit, since such handling may cause the magnet to fracture and separate from the tool.